Various devices for supporting elevated beds of trucks are known. U.S. Pat. No. 3,135,555, issued to MeCaskey, is directed to a safety guard for hydraulic hoists. As shown in FIG. 1, the body frame 20 of a dump truck body 15 is raised and lowered via two hydraulic rams 22. The rams 22 have a cylinder 25 and a rod 26 that is coupled at its free end 29 via bosses 30 to a cross rod 31 as shown in FIG. 1. A safety guard 35 is shown in FIG. 2 for embracing the rod 26 and locking the hydraulic ram in an extended condition. The guard 35 comprises a tube 36 split lengthwise to provide half sections 39 and 40 that are hingedly connected so as to open up for fitting around the rod 26 of an hydraulic ram. The two guard halves 39 and 40 are preferably connected along one meeting line (37) by a single piano hinge 45. At the other meeting line 38, two ears 59 and 60 are welded to the half sections 39 and 40. Each of the ears has a bore through which a locking means 55 such as a hook, pin, bolt or the like can be used to hold the ears together. In the embodiment shown in the figures, a bolt 72 extends through the bores and is secured by a nut 73.
In U.S. Pat. No. 3,157,435, issued to Sherven, a safety device is shown for use on dump trucks, trailers, and similar vehicles. FIGS. 2 through 7 illustrate the. structural features of safety prop A. A flat baseplate 10, which is adapted for mounting on one of the cross members of the truck frame B, is equipped with a pair of laterally spaced upstanding apertured lugs 12, 14 into which a hinge pin 16 is received and held in place by cotter pins 18. As shown in FIG. 1 and FIGS. 8 through 11, the axis of hinge pin 16 is generally horizontal permitting safety prop A to rotate in a limited vertical plane with respect to frame B of truck C. Further included is hollow generally elongated cylindrical supporting member or barrel 20 having a solid lower end plate 22 from which extend longitudinally therefrom a pair of spaced apertured lugs 24, 26 adapted to pivotally mount upon hinge pin 16 between lugs 12 and 14 of base plate 10. A dump truck body engaging member or piston 30 is telescopically positioned within supporting member 20. As shown in FIGS. 2 and 3, a compression spring member 50 is mounted within supporting member 20. Releasable latching means is provided for holding member 30 in a retracted position within member 20.
In the Sherven device, the safety prop A is separate and apart from the hoisting mechanism E that can be actuated to raise the dump body D as shown in FIG. 8. After actuating hoisting mechanism E, the spring member 50 of safety prop A is released to extend member 30 and jaw 40 into engagement with the cross member 41 of dump body D. Then hoisting mechanism E is actuated to let the dump body D settle onto the jaw 40. In this manner, the weight member 30 is pushed into a latched or cocked position within member 20 as shown in FIG. 9. When not needed, the safety prop can be deployed or lowered into the position as shown in FIG. 11.
A locking device for a bulldozer and backhoe is described in U.S. Pat. No. 4,373,851 issued to Confoey. In particular the locking device is for use on equipment that has hydraulic pistons and cylinders. The Confoey device is a split cylindrical sleeve 10 that has an annular flange 19 at one end and arms 20 and 21 at the other end. The split cylindrical sleeve 10 is formed of equal half sections 11 and 12 that have a pair of pivot hinges 13 therebetween as shown in FIGS. 2 and 3. A pin 16 can be positioned through apertures in L shaped extensions 14 and 15. The pin 16 is secured to the aperture in extension 15 by welding. The pin 16 also extends into a bore in extension 14. Pairs of lugs 17 and 18 are secured to the half sections 11 and 12 on the opposite side of the extensions 14 and 15. Padlocks can pass through apertures in lugs 17 and 18. In this manner the half sections 11 and 12 can be secured about a rod R of cylinder assembly 30 of a backhoe 25. The flange 19 can abut with the end of the piston and cylinder assembly. The opposite end of the split cylindrical sleeve engages the boom 27.
While the above noted devices are beneficial to some degree, they each have limitations that do not make them suitable for use in supporting elevated antenna platforms such as those used by the U.S. Army.
Improperly designed mechanical structures can have catastrophic consequences when such structures fail. One such example involves the gusset plates on the Interstate 35 bridge in Minnesota. Old photos of the bridge show two gusset plates that were visibly bent as far back as 2003. That was four years before the bridge span collapsed into the Mississippi River. In that incident, 13 people were killed.
Another incident involves the Nov. 15, 1988 collapse of the 300 foot telescope in Green Bank, W. Va. It was discovered that the collapse was the result of the sudden failure of a gusset plate in the box girder which provided the main support for the antenna.
In the case of the AN/TPQ-37(V)9 Radar Antenna, there has been one unfortunate accident in which the antenna fell during maintenance and a soldier was killed. Hence there exists a need for an improved safety brace for use with such Radar Antennae.